缩放、旋转和平移的投影演示 先打开一个.zlg文件 滑动鼠标滚轮进行缩放 移动鼠标同时按住中键进行旋转 移动鼠标同时按住左键与右键进行平移 框架MFC编写-zoom, Rotation and translation of the projector to open a demo. zlg paper sliding scale for the mouse wheel while holding down the mou